1) P.f of inductive load is corrected by connecting . across it. 2) Open circuit test measures.. losses. 3) The output variables of a motor are .. and. 4) For a motor output power is given by . 5) Flux control, voltage control, and armature control are three methods for.... of dc motor. 6) A transformer takes 100V at primary and gives 50V at secondary, its turn rati equals .... .... ..... 7) The given set of equations represents . la = IL, ミと Rf Ea – laRa = Vr , 8) The given set of equations represents. . Ea – laRa = Vr , la = !, + I , VT %3D %3D 9) The given set of equations represents . Ea – laRa – IseRse = Vr, la = Ise = I, %3D 10).. has more initial torque than shunt dc motor.

1) P.f of inductive load is corrected by connecting . across it. 2) Open circuit test measures.. losses. 3) The output variables of a motor are .. and. 4) For a motor output power is given by . 5) Flux control, voltage control, and armature control are three methods for.... of dc motor. 6) A transformer takes 100V at primary and gives 50V at secondary, its turn rati equals .... .... ..... 7) The given set of equations represents . la = IL, ミと Rf Ea – laRa = Vr , 8) The given set of equations represents. . Ea – laRa = Vr , la = !, + I , VT %3D %3D 9) The given set of equations represents . Ea – laRa – IseRse = Vr, la = Ise = I, %3D 10).. has more initial torque than shunt dc motor.

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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Similar questions

ELECTRICAL MACHINES 2 Describe the difference in construction operation of dc shunt, series, and compound motor. Compare the speed characteristics of dc shunt, series, and compound motor.
a.) full loadb.) half load
A three-phase, 4-pole, 1,500 rpm alternating having a double layer-windings with 18 turns per coil. The slots per pole per phase are 10 and the coil span is 22 slots. The spread phase is 60 degrees and the flux per pole is 0.0625 Weber. If the armature windings are wye connected. a) Determine the generated voltage per phase and the line to line voltages. b) If the alternator is delivering a three - phase load of 1,200KW at 0.8 lagging power factor what is the line current of the alternator
32. An alternator requires an alternating current of 2.1 A to produce on short circuit its full-load current of 50 A. The same on open-circuit an emf of 320 V. The armature resistance is 1Ohms . Find the full-load percentage regulation with a lagging p.f. of 0.6 when terminal p.d. on load is 2000 V. A. 7.2% B. 28.8% C. 3.6% D. 14.4%
4. A 2 MVA, 2.3kV, three-phase Wye connected alternator operates at rated kVA at a power factor of 80 %. The dc armature winding resistance between terminals is 0.08-ohm. The field takes 70-A at 125-V from the exciter equipment. Friction and windage loss is 20-kW, iron loss 36-kW and stray power loss are 2.0-kW. Calculate the efficiency of the alternator. Assume the effective armature winding resistance is 120% of the dc resistance.
the basic requirement of DC armature winding is that it must be: a) a closed one b) a lap winding c) a wave winding d) either (b) or (c)
Determine the efficiency of a 1500kVA, 2300 V, 3 –phase, Y – connected alternator which operates at rated output with a power factor of 80%. The DC armature resistance at 70º C between terminals is 0.08 ohm. The field takes 70 A at 120 V from the exciter equipment. Friction and windage losses are 15kW, iron loss is 35kW and stray load losses is 15 kW. Assume the effective armature winding resistance is 1.5 times the DC value. a. 94.56 % b. 90.31 % b. 93.35 % d. 92.62 %
The field current of a separately-excited dc motor operating with a fixed armature voltage and a fixed mechanical load is changed. This causes the speed to increase. The field current has been: Select one: O a. This is not possible because the speed is independent of the field current. O b. decreased. O. increased. O d. None of the above. A single phase transformer is rated at 10KVA, 220/108. If a load resistance 1.5 ohm is connected across 108 V winding, calculate the transformer efficiency (in percent) if the total losses in the transformer is 2746W? Answer: Synchronous generator will produce sufficient electrical power output if it is given: Select one: O a. Ac current. O b. Mechanical power input and dc field current. O. Mechanical power input only. O d. Mechanical power input and Ac filed current.
Exercise 2 A shunt generator delivers 14A at 270V and the resistance of the shunt field and armature are 100 Q and 0.75 Q2, respectively. Calculate: i. The generated emf and the efficiency of this operating condition. ii. The generated emf if the shunt field impedance was triple and if it was double and the efficiency of these cases. iii. What emf could serve tha same active power of load but at load voltage of 240V and the efficiency in this case.
Rotor current is about ................. A * Starting torque is .................... N.m * Speed at maximum torque is ............. r.p.m Input current is ............. A *
Subject: Electrical Machines
Two DC generators, each with armature resistance of 0.02 ohm and fieldresistance of 50 ohms run in parallel and supply a total current of 1000 amperesto the load circuit. If their emfs are 270 V and 265 V, their bus bar voltagewill be. [Ans. 267.5 V]